INTERVENTIONAL NEURORADIOLOGY Flow diversion for complex middle cerebral artery aneurysms Mario Zanaty & Nohra Chalouhi & Stavropoula I. Tjoumakaris & L. Fernando Gonzalez & Robert Rosenwasser & Pascal Jabbour Received: 9 November 2013 /Accepted: 30 January 2014 # Springer-Verlag Berlin Heidelberg 2014 Abstract Introduction This study aims to evaluate the safety and effi- cacy of flow diversion for treatment of large and complex middle cerebral artery (MCA) aneurysms. Methods We conducted a retrospective review of the clinical charts of all patients who underwent Pipeline Embolization Device (PED) placement for aneurysm at our institution from October 2010 to October 2013. We included ten patients, of which five had large MCA aneurysms and three had giant ones. Fusiform unruptured aneurysms represented seven of all ten an- eurysms. Angiographic and clinical follow-up were available for all patients mostly between 7 and 12 months. Results We had no technical complications, one periprocedural morbidity, and no mortality. On follow- up, we had no hemorrhagic complications, no aneu- rysms rupture, and only one clinically significant throm- boembolic event in a patient who discontinued antiplate- let therapy against medical advice. One patient had completely occluded his diseased vessel but remained asymptomatic. The overall complication rate is 3/10. On follow-up, complete occlusion occurred in seven patients (7/9). Conclusion PED treatment for large, giant, and bifurca- tion MCA aneurysms was feasible, with satisfying complete occlusion rate, no mortality, and reasonable morbidity rate. Keywords Pipeline Embolization Device . Flow diversion technique . Large middle cerebral artery aneurysm . Bifurcation aneurysm . Complex middle cerebral artery aneurysm Introduction Middle cerebral artery (MCA) aneurysms represent the third most common cause of subarachnoid hemorrhage (SAH) and almost one fifth of unruptured aneurysms (UAs) [ 1]. Those arising from bifurcation represent 85 % of all MCA aneurysms. They tend to be wide- necked and incorporate one or more branch vessels. The risk of occluding branch vessels as well as the risk of coil herniation has classically favored microsurgery over endovascular intervention. Technique such as stent- assisted coiling (SAC), balloon remodeling, and Y- stenting with or without coiling have been employed for the treatment of MCA aneurysms, but results remains suboptimal [2]. Hence, we opted for flow diversion as an alternative endovascular treatment. The Pipeline Embolization Device (PED) is a dedicated flow diverter used for treating aneurysms of various sizes and shapes. Experiences with the device have been mostly limited to aneurysms arising from the internal carotid artery. Little data exists on the safety and efficacy of PED in MCA aneurysms. Although other flow diversion devices exist in the market, the majority of the available data is on the use of PED, and it is the only FDA-approved flow diverter in the USA; the other flow diverters can be used in the context of a trial. Therefore off-label use is only allowed with PED. M. Zanaty : N. Chalouhi : S. I. Tjoumakaris : L. F. Gonzalez : R. Rosenwasser : P. Jabbour Department of Neurosurgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA P. Jabbour (*) Division of Neurovascular Surgery and Endovascular Neurosurgery, Department of Neurological Surgery, Thomas Jefferson University Hospital, 901 Walnut Street 3rd Floor, Philadelphia, PA 19107, USA e-mail: pascal.jabbour@jefferson.edu Neuroradiology DOI 10.1007/s00234-014-1339-x